Update cpp/change-notes/2021-06-10-std-types.md

Co-authored-by: Jonas Jensen <jbj@github.com>

Author: jsinglet

cpp/change-notes/2021-06-10-std-types.md

@@ -1,4 +1,4 @@
 lgtm,codescanning
 * Added definitions for types found in `cstdint`. Added types `FixedWidthIntegralType`, `MinimumWidthIntegralType`, `FastestMinimumWidthIntegralType`, and `MaximumWidthIntegralType` to describe types such as `int8_t`, `int_least8_t`, `int_fast8_t`, and `intmax_t` respectively. 
 * Changed definition of `Intmax_t` and `Uintmax_t` to be part of the new type structure. 
-* Added a type `FixedWidthEnumType` which describes enums based on afixed-width integer type. For instance, `enum e: uint8_t = { a, b };`.
+* Added a type `FixedWidthEnumType` which describes enums based on a fixed-width integer type. For instance, `enum e: uint8_t = { a, b };`.